Sounds like a breeder's dream: Researchers in Dublin say they've identified a speed gene, with variations that predict whether a racehorse is better suited for short-distance sprints or longer tests of stamina. Comparing the genetic codes of 179 winners with their track records, they identified three variants of the myostatin gene, which regulates muscle mass, associated with maximum performance in short, middle, and long distance racing. A commercial blood test, at $1,400 a pop, will be available for breeders by the end of the month, Bloomberg reports.
(More gene sequencing stories.)